Agitator and grate for fire beds



Sept. 30, 193 w. B. QHAPMAN AGITATOR AND GRATE FOR FIRE BEDS Filed July 29, 1926 4 Shsets-Sheet Sept. 30, 1930. w. B. CHAPMAN 3 AGITATOR AND GRATE FOR FIRE BEDS v Filed July 29, 1926 4 Sheets-Sheet 2- mm l l l I l awpemboz P Mam 9. Map $51 1 Gum/14 I 93.0w. (We! MA QM Sept. 3@, 1930. CHAPMAN 1,777,138

AGITATOR AND GRATE FOR FIRE BEDS Filed July 29, 1926 4 Sheets-Sheet 3 ngENTbR 16%LW @M Ran ATTORNEY p 3Q 1930. w. B. CHAPMAN AGITATOR AND GRATE FOR FIRE BEDS Filed July 29, 1926 4 Sheets-Sheet 4 BY @OL&PM#%LQA A TTORNEYS.

Patented Sept. 30, 1930 UNITED STATES PATENT OFFICE WILLIAM B. CHAPMAN, OF JACKSON HEIGHTS, NEW-YORK, ASSIGNOR TO CHAPMAN ENGINEERING COMPANY, OF MOUNT VERNON, OHIO, A CORPORATION OF OHIO AGITATOR AND GRATE FOR FIRE BEDS Application filed July 29,

The invention aims to provide a combustion apparatus wherein substantially uniform conditions of combustion may be maintained, particularly as regards the steps of introduc- & ing the blast, agitating the fire bed to elimi nate blow holes, distribute the fuel evenly, and removal of the ash evenly from all parts of the ash bed and at a rate conforming substantially to the rate of ash production.

to The invention although of general utility in apparatus for partial or complete combustion of fuel, is particularly desirable in connection with the generation of producer gas wherein the blast has usually been introduced through a central tuyere-hood and the ash has been removed by moving it outwardly to the periphery of the, ash bed beyond the conlines of the producer walls, which has resulted in non-uniform blast conditions due to the localized points of admission of the blast, as well as non-uniform conditions as regards removal of the ash from different areas in the ash bed. When the ash is removed only from the periphery of the ash has to travel a greater distance to the point of removal, resulting in a less rapid ash ejection from the central areas of the fire bed. The invention also applies to the generation of water gas and the like. According to the present invention, I elimimate the objectionable peripheral ash discharge by removing the ashes directly through the grate. For this purpose I employ an agitating member which sweeps through the bottom of the fire bed and operates in conjunction with a grate adjustable as regards the size of the grate openings, whereby the agitating member breaks up the ash to small sizes which will pass through the grate openings directly downward and uniformly from all areas of the ash bed, and at the same time the blast may be introduced through the grate openings so as to pass up evenly through all parts of the fire bed. The agitating member is both upstroking and out-stroking in its action and accordingly conditions the fire bed not only in its imme- F diate vicinity but for a substantial distance bed the ash in the central area of the fire bed 1926. Serial No. 125,619.

above, and also closes blow holes that always tend to form along the walls.

By adjustment of the size of the grate openings, the rate at which the ash is removed may be made to correspond with the rateof ash production, thus permitting the agitator to be operated at any desired speed suitable for conditioning the fire bed, without ejecting ash at an undesired rate.

The invention also includes cetain special features of cooling the agitator and the grate by contact with wet ash, and also features relating to the disposal of the ash after passing through the grate, as well as other objects and advantages which will be in part obvious andin part specifically pointed out in the description hereinafter contained which taken in conjunction with the accompanyir g drawings disclose certain preferred embodiments of the invention. Such embodimems however are to be considered merely as illustrative of its principles. In the drawings- Fig. l is a central longitudinal section of a gas producer constructed in accordance with the invention.

Fig. 2 is a plan view of the apparatus shown in Fig. 1.

FFig. 3 is a detailed section on line 33 of Fig. 4 is a view similar to Fig. 1 but illustrating a modified form of agitator and grate construction.

Fg. '5 'is a plan view of the apparatus shown in Fig. 4.

Fig. 6 is a transverse section of the agitating member shown in Fig. 5.

In the apparatus illustrated in Figs. 1 to 3 the fire bed is surrounded by the annular generator walls 1 and supported on a grate denoted generally by numeral 2, the agitating member 3 being shown in the form of a beam overlying the grate in substantially diametrical position. and supported by a hollow post 4, which is disposed within a central opening 5 in the grate and also serves to impart rotary motion to the agitator, preferably by the structure which is described hereinafter in greater detail.

The agitating member 3 turns around in the lower portion of the ash bed and is both upstroking and outstroking in its action, preferably being provided with inclined forward surfaces 6 (Fig. 2) to agitate the fuel bed thoroughly for a substantial distance above the grate and pack the fire bed more tightly along the walls, thereby eliminating blow holes and maintaining uniform conditions of combustion throughout the fire bed. Preferably an annular water cooled wear plate 7 having ribs 8 thereon surrounds the agitator so that should any large clinkers be made by improper operation, they will be forced outwardly by the beam and ground up between the outer ends of the agitator and the ribs of the wear plate. Furthermore, the ribs 8 act to retard the horizontal movement of the lower portion of the firebed, which is caused by the rotation of the agitating member.

As above stated the grate 2 is so constructed that the effective size of the grate openings as regards ash removal may be adjusted. No particular specific structure for accomplishing the above result is essential but in the form of the invention illustrated in Figs. 1 to 3 the grate is made up of upper and lower sections 9 and 10 respectively, the upper section being fixed to and supported by the wear ring 7 and provided with a series of concentric arcuate openings 11. As is best shown in Fig. 2 the upper grate section 9 preferably is made up of sector shaped sub-sections 12 which fit together to form a complete circle and each section furthermore is preferably provided with an inner arcuate depending flange 13 (Fig. 1) in such manner that all of these flanges make up a rigid hub which is secured to a tie ring 14, thereby preventing sagging of the central portion of the grate.

The lower grate section 10 also preferably is made up of sector like sub-sections similar to members 12 above described and having similar openings 15 therein, the lower grate sections being supported by ledges 16 depending from the upper sections in such manner that the lower sections may slide radially with regard to the'upper sections, thus throttling the flow of ashes through theopenings in the upper sections. As shown each lower grate section is adjustable by means of a rod 17 extending outwardly therefrom and connected to an operating handle 18 mounted on the outside of the producer wall.

The lower grate sections are spaced from the upper sections to such an extent that the adjustment of the lower sections to provide difierent grate openings does not alter the fiow of the blast upwardly through the grate to any substantial extent, since only small adjusments of the eflective grate opening area are necessary to secure the desired range of rate of ash removal.

In the form of the invention illustrated in Figs. 1 to 2, the ash passing through the grate drops down onto a rotary table 19, supported on ball bearing race-way 20 and carrying the hollow post 4 above mentioned, which both supports and drives the agitating member. Rotation is imparted to table 19 and the agitating member 3 by providing a large gear-ring 20 around table 19 and a pinion 21 driven from certain other gears which need not be described in detail.

The gas generator shown in Fig. 1 has a gas tight housing 22 surrounding the space beneath the grate and the ash deposited upon rotary table 19 is removed from the latter by a fixed sweep 23 which discharges the ash into a water sealed chamber 24 from which latter the ash may be removed in any suitable manner. The depth of said'seal varies according to whether'producer gas or water gas is to be made.

As shown in Fig. 1, the agitating member 3 is water cooled by means of concentric inlet and outlet pipes 25 and 26 which pass upwardly through a rotary joint 27 and into agitating member 3 through its axis of rotation, the inlet pipe 25 being provided with 90 branches 25 which lead the cooling water into both arms of the agitating member.

In the operation of the apparatus above described the agitating member as it turns around immediately above the grate will serve to agitate the fire bed for a substantial distance above and will also grind up the ash to a size small enough to pass through the grate openings 11 and 15. The agitating member being located just above the grate, also sweeps the grate clean of any obstructions which otherwise might tend to clog the grate openings. Any large clinkers in the neighborhood of the agitating member will be ground up by the beam as it crowds the clinkers and ashes against the annular-wear ring 7. 'The rate of rotation of the beam may be adjusted to conform to the rate best suited for conditioning the fire bed and the grate openings may be adjusted so as to permit ash to fall through the grate at a rate substantially equal to the rate of ash production. The grate also will permit the blast to pass up uniformly to the different parts of the fuel bed, the blast being admitted through any suitable opening 28 beneath the grate. The grate is equally suited to the downward flow of Water gas, in which case the blast opening also serves as a gas exit.

In Figs. 4 to 6 the invention is shown as applied to a gas'generator of the dry bottom type with certain special features to provide adequate cooling for the agitating member. In Fig. 4 I have shown a gas generator having side walls 29 and a grate denoted generally by numeral 30, the agitating member 31 being supported and driven by means of a central hollow post 32 similar to member 4 I above described. An annular wear ring 33 1;)

shown in Fig. 4, the grate section 36 being.

stationary. Lower grate sections 38 are provided in the form of concentric rings which rest upon eccentrics 39 carried by a suitable number of shafts 40 extending radially under the grate whereby by turning the shafts by means of suitable operating handles 41 the elevation of the lower grate sections 38 may be adjusted. This adjustment therefore controls the rate at which the discharge of ash through the grate openings will be permitted without however afiecting to any substantial extent the How of the blast or gases through the grate.

In the form of the invention illustrated in Figs. 4 to 6 the blast is introduced by means of a pipe 42 leading to the s ace beneath the grate, the lower portion 0 the gas generator being enclosed within the gas-tight housing 43. The ash falling onto table 35 is also confined thereon by means of an annular wall 44 located above the table, until the ash passes around to a fixed sweep 45 which removes the ash during on opening 46 in wall 44 and permits it to drop down into an ash pit 47 This form of the invention also provides for exteriorly cooling the agitating member by contact with wet ash carried by the grate. As shown the grate section 36 is provided with a series of annular water troughs 48 which are in communication with each other through the gaps 49 between adjacent grate openings 37, the troughs 48 having suitable inlet and outlet water connections 50 and 51 leading thereto whereby the ash within the troughs is constantly saturated with water. The agitating member 31 furthermore is provided with inclined tongues52 which extend down into the troughs 48 and thus cause the wet ash to pass upwardly over the inclined forward surfaces 53 of the agitator and over the top thereof. Between the annular Water troughs are gaps for the passage of the ashes and gases. Thus the grate partakes of the advantages of both the wet and dry bottom types. As shown the agitating member is also provided with openings 54 in its rear walls whereby the blast in passing through these openings also serves to cool the agitator. Thus the necessity of providing special pipe connections to keep the rotating agitating member filled with cooling water is avoided and the structure as a whole lends itself well the dry bottom type. T

The general mode of operation of the gas generator shown in Figs. '4 to 6 is similar to that above described in connection with Figs. 1 to 3, that is to say, that the agitating member is slowly rotated through the bottom of the fire bed to distribute fuel evenly over the fire bed, eliminate blow holes and grind up the ash to such small size as will pass through grate openings 37. The lower grate sections 38 also will be adjusted to peimitthe ejection of ash at a rate corresponding substantially to the rate of ash production, thus making the operation of the generator continuous.

While certain specific embodiments of the invention have been disclosed it will be obvious that many changes may be made therein without departing from its principles as defined in the appended claims.

I claim:

1. In combination, a grate supporting a fire bed, an agitating member overlying said grate, a rotary driving member for said agitator extending up through the grate, an ash receiving table disposed beneath the grate and moving with said rotary member, and means for removing ash from said table, and a water sealed ash pit beneath said sweep adapted to receive ash removed from the table by the sweep.

2. In combination, a grate supporting a fire bed, an agitating member overlying said grate in position to operate in the ash carried by the grate, and means for supplying cooling water to the ash immediately above the grate whereby said agitating member may be cooled by contact with such wet ash.

3. In combinaiton, a grate supporting a fire bed, having one or more troughs with means for supplying cooling water thereto, an agitating member overlying said grate in position to operate in the ash immediately above said grate, whereby said agitating member may be cooled by contact with the ash which is wet by the water in said trough.

4. In combination, a grate supporting a fire bed, and having'one or more annular troughs therein, with means for supplying cooling fluid to said troughs, an agitating member overlying said grate having one or more projections extending into such troughs and means for producing relative rotation between said agitating member and grate to gas generators of whereby said projections cause wet ash to flow past the agitating member to cool the latter.

5. In combination, a grate supporting a fire bed, an agitating member overlying said grate, said grate being provided with troughs with cooling water connections leading thereto, and also with openings for the passage of the blast.

6. In combination, a grate supporting a fire bed, an agitating member overlying said grate, said grate being provided with troughs with cooling water connections leading thereto, and also with openings for the passage of the blast, said agitating member being open at its bottom to receive a portion of the blast and being provided with exit openings near its top to permit a portion of the blast to flow therethrough.

7. In combination, a grate supporting a fire bed, an agitating member overlying said grate and open at the bottom to receive a portion of the blast passing through said grate, said member having openings near the top for the exit of said portion of the blast.

8. In combination, a grate supporting a firebed, a sidewall adapted to surround the rirebed, an agitating member overlying said grate, means for producing relative rotation between said grate and sidewall on the one hand and said agitating member, said agitating member being directly above the grate and extending out substantially to said sidewall, whereby the agitating member grinds up the ash into sizes which will pass through the grate openings and adjustable means for throttling the discharge of ash through the grate.

9. In combination, a grate supporting a firebed, a sidewall adapted to surround the firebed, an agitating member overlying said grate, means for producing relative rotation between said grate and sidewall on the one hand and said agitating member, said agitating member being directly above the grate and extending out substantially to said sidewall, whereby the agitating member grinds up the ash into sizes which will pass through the grate openings, the grate having openings the upper portions of which are fixed and the lower portions of which are adjustable to throttle the discharge of ash through the grate.

10. In combination, a grate supporting a firebed, a sidewall adapted to surround the firebed, an agitating member overlying said grate, means for produci'n relative rotation between said grateand si ewall on the one hand, and said agitating'member, said agltating member being directly above the grate and extending out substantially to said sidewall, whereby the agitating member grinds np the ash into sizes which will pass through the grate openings, said grate being composed of an upper section which is fixed in posi* tion and a lower section which is movable to throttle the flow of ash through the grate.

11. In combination, a grate adapted to support a firebed, a wall adapted to surround the firebed, an agitating member overlying said grate, means for moving said agitating member horizontally through the firebed,

means comp-rising inwardly projecting parts.

on said wall for retarding the resultant horizontal movement of the firebed, and adjustable means for regulating the flow of ash through the grate.

12. In combination, a stationary grate supporting a firebed, a rotary agitating member overlying the grate, a rotary ash-receiving table underlying substantially all parts of the grate so as to receive substantially all ash dropping through the grate, means for rotat-' ing said table, said table being connected. to said agitating member by a part extending up through the grate to cause the agitating member to turn with the table, and a stationary sweep operating over the table to discharge the ash therefrom.

13. In combination, a stationary grate supporting a firebed, a rotary agitating member overlying the grate, a rotary ash-receiving table underlying substantially all parts of the grate so as to receive substantially all ash dropping through the grate, means for rotating said table, said table being connected to said agitating member by a part extending up through the grate to cause the agitating member to turn with the table, a gas-tight housing surrounding said grate and table, a stationary sweep operating over the table to discharge the ashes therefrom at a local point, and means permitting removal of the ash through the gas-tight housing.

1 1. In combination, a firebed support adapted to underlie a firebed, a sidewall adapted to surround the firebed, an agitating member overlying said firebed support, said agitating member being directly above said support and extending out substantially to said sidewall whereby the agitating member grinds up the ash into sizes which will pass through the hereinafter mentioned ash discharge openings, said firebed support providing ash-discharge openings at the bottom of the firebed, and means for adjusting the size of: at least a portion of said openings, to regulate the flow of ash therethrough.

In testimony that I claim the foregoing, I have hereunto set my hand this Q lth day of July, 1926.

IVILLIAM B. CHAPMAN. 

